For a particle executing SHM, the displacement `x` is given by `x = A cos omegat`. Identify the graph which represents the variation of potential energy `(PE)` as a function of time `t` and displacement `x`.
(a) `I, III`
(b) `II, IV` (c ) `II, III`
(d) `I, IV`
A. `I.III`
B. `II.IV`
C. `II,III`
D. `I,IV`
